Add project-user association normalization script to 4.20.1 upgrade

[winterhazel]

Description

This PR adds the cleanup script from #10008 to the 4.20.1.0 upgrade in order to normalize environments that were updated to 4.20 and will not go through the 4.19.2 script.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)
• build/CI
• test (unit or integration test code)

Feature/Enhancement Scale or Bug Severity

Bug Severity

• BLOCKER
• Critical
• Major
• Minor
• Trivial

How Has This Been Tested?

Without the changes in #10008, I created some broken projects by deleting their users. Then, I executed the upgrade script and verified that I was able to list their accounts/users normally.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 16.03%. Comparing base (ac19379) to head (09d85a7).

Additional details and impacted files

@@            Coverage Diff            @@
##               4.20   #10116   +/-   ##
=========================================
  Coverage     16.03%   16.03%           
- Complexity    12814    12815    +1     
=========================================
  Files          5637     5637           
  Lines        493507   493507           
  Branches      59831    59831           
=========================================
  Hits          79131    79131           
  Misses       405600   405600           
  Partials       8776     8776           

Flag	Coverage Δ
uitests	4.02% <ø> (ø)
unittests	16.87% <ø> (ø)

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